A conventional sailboat, in order to reach a stable orientation, will generally heel or roll in response to the force of the wind caught by its sails. Consequently, the component of sail area available for forward thrust is considerably reduced. Further, the water pressure distribution acting on the sailboat hull varies as a function of the degree of heeling, as do stresses from the transfer of the wind forces from the sails to the deck and hull. Consequently, the sailboat deck and hull in particular are generally configured of a heavier nature than would be necessary if the sailboat were always generally vertically oriented. Therefore, the provision of attitude control means for maintaining the sailboat in a vertical orientation can provide the benefits of both a lighter weight hull and deck and the availablity of the full sail area oriented for producing forward thrust.
Most sailboats include a keel which is either fixedly mounted or generally vertically retractable.